This invention relates to a method for processing a light-sensitive silver halide color photographic material. More particularly, it pertains to a method for processing a light-sensitive silver halide color photographic material which is capable of rapid developing processing and which is improved in processing stability in said rapid developing processing, or a method for processing a light-sensitive silver halide color photographic material in which fluctuation of minimum density (Dmin) at the running processing can be prevented and also lowering of maximum density (Dmax) can be prevented with maintaining preservability (stability during preservation) of the color developing solution.
In recent years, in this field of art, it has been desired to develop a technique which is capable of rapid processing of a light-sensitive silver halide color photographic material and yet also excellent in processing stability to thereby produce stable photographic characteristics.
More specifically, for light-sensitive silver halide color photographic material, running processing has been practiced by an automatic developing machine provided at each laboratory, and as a part of improvement of services to users, it has been demanded that the developing processing of the material be completed returned within the very day on which the material was received. Recently, it has been demanded to return the material even several hours after receipt. Thus, development of a technique capable of rapid processing has been in great demand.
To review the prior art regarding rapid processing of light-sensitive silver halide color photographic material, the techniques may be broadly classified into:
[1]the technique through improvement of light-sensitive silver halide color photographic material;
[2]the technique through physical means during developing processing; and
[3]the technique through improvement of the processing solution composition to be used in developing processing.
Concerning the above [1], there may be included (1) improvement of silver halide composition (e.g., fine grain formation as disclosed in Japanese Provisional Patent Publication No. 77223,/1976, the lowered silver bromide technique of silver halide as disclosed in Japanese Provisional Patent Publication No. 784142/1983, or Japanese Patent Publication No. 18939/1981); (2) use of an additive (e.g., the technique of adding a 1-aryl-3-pyrazolidone having a specific structure to light-sensitive silver halide color photographic material as disclosed in Japanese Provisional Patent Publication No. 64339/1981 or the technique of adding a 1-aryl-pyrazolidone to light-sensitive silver halide color photographic material as disclosed in Japanese Provisional Patent Publications No. 144547/1982, No. 50534/1983, No. 50535/1983 and No. 50536/1983); (3) the technique of a high speed reactive coupler (e.g., the technique of using a high speed reactive coupler as disclosed in Japanese Patent Publication No. 10783/1976, Japanese Provisional Patent Publications No. 123342/1975 and No. 102636/1976); and (4) the thin film formation technique of photographic constituent layers (e.g., the thin film formation technique of photographic constituent layers as disclosed in Japanese Patent Publication No. 204992/1985).
Concerning the above [2], there is the stirring technique of processing solution (e.g., the stirring technique of processing solution as disclosed in Japanese Patent Publication No. 23334/1986).
Concerning the above [3], there have been known (1) the technique of employing a developing accelerator; (2) the technique of thickening the color developing solution; and (3) the technique of lowering the concentration of halide ions.
The present invention, from among these rapid processing techniques of [1], [2]and [3], concerns the above [3]. Processing of light-sensitive material comprises basically the two steps of color developing and desilverization. Said desilverization comprises the steps of bleaching and fixing or the step of bleach-fixing. Otherwise, as additional steps, rinsing processing, stabilizing processing, water washing or stabilizing processing substituted with water washing may be added. More specifically, in color developing, the silver halide exposed is reduced to silver and at the same time the aromatic primary amine developing agent reacts with a coupler to form a dye. During this process, halide ions formed by reduction of silver halide are dissolved in the developing solution to be accumulated therein. Also separately, the components such as inhibitor, etc. contained in the light-sensitive material are also dissolved in the color developing solution to be accumulated therein. In the desilverization step, the silver formed by development is bleached with an oxidizing agent, and then all the silver salts are removed with the fixing agent as soluble silver salts from within the light-sensitive material. Also known is a the one bath bleach-fixing processing method in which the bleaching step and the fixing step are processed all at once.
Of the techniques for improving the processing solution composition, the present inventors have investigated (2) the technique of thickening the color developing solution to be used for developing processing of the above [3]. This technique is a method for increasing activity by increasing the color developing agent in the color developing solution during the color developing step, but due to the extremely expensive cost of color developing agent, the processing solution becomes relatively higher in cost and at the same time the above developing agent is difficultly soluble in water to be unstably and easily precipitated. Thus, it has been found to be practically unapplicable.
Accordingly, the present inventors have investigated (3) the technique of lowering the halide ion concentration. Of the techniques through improvement of processing solution composition to be used for development processing of the above [3]. This technique is a technique which increases the development activity by increasing the amount of color developing solution supplemented to thereby to lower the halide ion concentration accumulated in the developing solution.
The present inventors have attempted to apply such a technique of lowering the halide ion concentration to various silver halide emulsions.
As described above, it has been known that the halide ion concentration in color developing solution has an influence on rapid processing, and a similar effect was also anticipated in the processing of internal latent type light-sensitive silver halide color photographic material.
According to the study of the present inventors, a color developing solution having a halide ion concentration, particularly a bromide ion concentration, in excess of 4.0.times.10.sup.-3 mole/liter may have an influence on both the surface latent image type emulsion and the internal latent image type emulsion. However, it has been found that the developing acceleration effect on the internal latent image type emulsion is very great when the developing solution has a halide ion concentration, particularly a bromide ion concentration of 4.0.times.10.sup.-3 mole/liter or less.
Particularly, it has been found that the effect of rapid processing for an internal latent image type emulsion containing a mercapto type inhibitor is marked in processing with a color developing solution having a bromide ion concentration of 4.0.times.10.sup.-3 mole/liter or less. Further, it has been found that the effect is great in a color developing solution containing substantially no benzyl alcohol.
In color developing, silver halide which had been exposed is converted into silver by reduction and at the same time an oxidized aromatic primary amine developing agent forms a dye by reacting with a coupler.
In the color developing solution to be used in such color developing, sulfites, or a water-soluble salt of sulfite and hydroxylamine is added as a preservative (antioxidant) in order to increase preservability thereof. Among them, in the color developing solution using a sulfite singly as in the former case, generation of fog becomes remarkably high as time lapse. Thus, as in the latter case, by combinedly using a water-soluble salt of a sulfite and hydroxylamine, the preservability of the developing solution is remarkably increased and the generation of fog in the lapsed developing solution is decreased.
However, handling hydroxylamine is extremely inconvenient since the general distributor of poisonous substances and powerful medicines requires its registration. A person must be appointed who is responsible for handling the hydroxylamine in order to handle and sell the salts based on the poisonous substances and powerful medicines management law.
Accordingly, when self-treatment at the shop or color copying loaded with a color development system is carried out in the future, it has strongly been desired to develop a preservative substituting for the hydroxylamine.
As the preservative substituting for the hydroxylamine, 2-anilinoethanol and dihydroxyalkene have been proposed in U.S. Pat. Nos. 3,823,017 and No. 3,615,503, respectively. However, these compounds are themselves unstable and have no preservative effect in a color developing solution.
On the other hand, in a developing solution (for black and white photography) containing hydroquinone or N-alkyl-paminophenol as the developing agent, sucrose has been known as a preservative, but sucrose seldom has any effect as a preservative in a color developing solution containing an aromatic primary amine as the developing agent.
Also, ascorbic acid and its derivatives have been known as preservative for both the developing solution for black- and-white photography developing solution and the color developing solution, but these materials have a defect of inhibiting color formation and causing a remarkable decrease in color density. Therefore, ascorbic acid and its derivatives are inferior to the hydroxylamine in the color developing solution.
Further, .alpha.-hydroxy-aromatic alcohols described in Japanese Provisional Patent Publication No. 7779/1977, hydroxamic acid compounds as described in Japanese Provisional Patent Publication No. 27638/1977, o-aminocarbonyl compounds described in Japanese Provisional Patent Publication No. 143020/1977, monosaccarides described in Japanese Provisional Patent Publication No. 102727/1977, and amino acid derivatives described in Japanese Provisional Patent Publication No. 140324/1977 have been disclosed.
However, when a large amount of monosaccarides or amino acid derivatives are employed, they show fairly good preservability, but they are easily decomposed by heat and have undesirable characteristics with respect to pollution.
D-glucosamine hydrochloride salt is the representative compound of the .alpha.-aminocarbonyl compounds, but the compound is inferior in preservability to hydroxylamines.
Also, while the hydroxamic acid compound has the same preservability as that of the hydroxylamine, it has the defect of high cost.
Thus, the present inventors have carried out development of the preservative having preservability (antioxidizing characteristics of the developing agent) substituting for the hydroxylamine. As a result, they have found that hydroxylamine derivatives are the most preferred preservatives but these compounds involve the following problems. That is, fluctuation of the minimum density (Dmin) at the running processing is large, and fluctuation of the maximum (Dmax) is also large, which has not been observed in the conventional hydroxylamine. However, according to further researches, it can be found that the above two problems can be solved by using an internal latent image type light-sensitive material having a specific silver halide.
Particularly, the effect of restraining fluctuation of the minimum density (Dmin) at the running processing is remarkable and it can be found that decrease of the maximum density (Dmax) can be prevented without decreasing preservability.